Belt drive means for an oscillating type of dry shaver



Sept. 15, 1959 M. D. SCHLEIFER BELT DRIVE MEANS FOR AN OSCILLATING TYPE OF DRY SHAVER Filed June 18, 1956 FIG.

' INVENTOR MORTON D. SCHLE IFER W MM) LT ATTORNEY -WT A United States Patent ()7 BELT DRIVE IVIEANS FOR AN OSCILLATING TYPE OF DRY SHAVER Morton D. Schleifer, West Hempstead, N.Y., assignor to Bulova Watch Company Inc., Flushing, N.Y., a corporation of New York Application June 18, 1956, Serial No. 592,043

1 Claim. (Cl. 30--43) This invention relates to electric shavers, and more particularly to the driving means by which the blades are motivated from the electric motor.

Noise level in operation of prior art electric shavers has been objectionably high and a disagreeable and detrimental characteristic of such devices. For the most part, the noise seems to be due to operation of intermeshing gears utilized in motivating the blades, the frequency of engagement of successive gear-teeth with each other setting up a resonance within the range of reception bythe human ear. Efforts have been made to reduce the noise by utilization of gears of different materials and by trial of other expedients, but without success.

In its basic concept, the present invention contemplates solution of the above-noted problem.

Also in its broad aspect, the invention proposes elimination of intermeshing gears as the driving means for the blades.

More specifically, the invention has for an objective the utilization of friction drive from the motor to motivate the blades of an electric shaver.

Another objectof the invention is to provide a friction drive wherein slippage is avoided.

Yet another object of the invention is to provide a friction drive wherein metal to metal contact between driving and driven elements is avoided.

Other objects, advantages and beneficial constructional features will appear to persons skilled in the art to which the invention appertains as the description proceeds, both by direct recitation thereof and by implication from the context.

Referring to the accompanying drawings, in which like numerals of reference indicate the same parts throughout the several views;

Figure 1 is a view partially in front elevation and partially in section on a plane through the middle of the shaver; V

Figure 2 is an end view of the shaver with a portion broken away for disclosing the driving means therein; and

Figure 3 is a sectional view of the driving means taken on line III-III of Fig. 2. p

In the specific embodiment of the invention illustrated in said drawings, and referring initially to Figures 1 and 2, the shaver comprises a body casing 20 of appropriate size and shape for a user to conveniently hold in one hand while operating. At what will arbitrarily be termed the top or nose end of said casing is a cap 21 fitting thereon and held in place by resilient latches 22. Said cap includes an inner metal frame 23 and an outer shell 24 of plastic or other desired material, said shell being held by frictional fit or otherwise on said frame.

For convenience of description and for orienting pur-. poses, it may be pointed out that in the arbitrary POSi-i tion shown in the drawings, the front and back of the exterior of the shaver are alike, and might therefore either be at the front or at the back, so for brevity here-. in, they will be referred to as the fronts. The rounded 2,903,789 Patented Sept. 15, 1959 ice side edges of the shaver integrally joining said fronts, although not having a definite line of demarcation from the fronts, will be referred to as the side edges of the shaver, and corresponding terminology will be employed indicative of direction as they may apply in the particular positions in which found in the drawings. Such terms as right and left, top and bottom are consequently to be understood as used with regard to locations and directions in the particular illustrations and not to be construed as restrictive.

The upper or forward nose end of said cap provides an elongated opening 25 extending from proximity of one side edge to the other side edge of the cap, exposing for the entire opening area a grill or comb 26 which is, for most of its exposed portion substantially a segment of a cylinder in shape and has the usual perforate shearing area that constitutes the portion of the shaver which is brought into contact with the hairy surface where shaving is to be performed in use, hereinafter also referred to as the face of the user. The front margins of the grill extend downwardly within the cap below said opening 25 and are suitably held in said cap and may accordingly be considered as a part of the cap.

Within body casing 20 is an electricv motor, designated in general by numeral 27, and protruding at one side of said motor is an armature shaft 28. On said protruding end of said armature shaft is secured adriving wheel which is continuously rotated'by said motor. In Figures 1 to 3, said driving wheel is designated by numeral 29.

Above said driving wheel, coplanar therewith, is a driven wheel 30. It is a feature of the invention to provide for frictional driving connection from said driving wheel to said driven Wheel, as will be dealt with more in detail hereinafter. 7

On the top of said motor, for rigid support thereby, is a shaving head constituted as an assembly attachable to said motor and including, in the present showing, a horizontally disposed double laminated sheet metal base plate 32. The laminations of said base plate are unified as by spot welding them together. At the opposite ends of the upper lamination of said base plate, the metal isbent upwardly to provide upstanding brackets 33 parallel one to the other and in planes perpendicular to the arma-z ture shaft. These brackets provide bearing support for ,a blade shaft 34 that extends parallel to the armature shaft. As will be presently observed, said blade shaft as herein illustrated has limited rotation imparted thereto and is caused to oscillate about its axis. At the end of the under lamination of the base plate toward the driven wheel is a depending leg 35 which functions as a bearing support for a stub-shaft 36 on which said driven wheel is mounted. An eccentric 37 is also mounted on said stub shaft and is integral with or otherwise made fast to the driven wheel at the side thereof toward the motor.

Aforementioned blade shaft 34 has one end protruding through its mounting bracket 33 to overlie said eccentrio, and on said end is secured a swinging arm 38 which depends from said shaft and straddles said eccentric 37 in diametrically opposed riding contact therewith so that as the eccentric'rotates, said arm will be swung back a'ndforth with a definite amplitude or angular disa Aforementioned blade-carriers 39 are for the purpose of mounting elongated blades 40' suitably spring-loaded for engagement of long edges of the blades with the inside surface of the cylindrical portion of the grill and to effect a'sweep of said'blades in a direction circumferentially of said grill; The said grill'provides a shaving area at its cylindrical portion with perforations therein-to ad'- mit the hair to be shaved, and'shearing is effected by the sweep of the blades across said perforations; By utilization of a plurality of blades injuxtaposition to said shaving area, the sweep'of each only has to traverse a part of the area and thus the sweep may be lessthan would be required to make a single blade traverse the entire area. Thusa restricted oscillation may be employed with attendant limited swing of the arm 38 and slower rotative speed of the motor and of the driving and driven wheels, all of which tends to reduce. the noise level. With the use of oscillating blades as above described, shearing is effected in both directions of movement of the blades, and it is therefore preferableto locate the-blades in planes which also include the axis of the blade shaft 34.

Thisreduction of noise level of which mention has just been made, is an essential feature of the present invention, and is further obtained by utilization of friction drive from the motor. Figures 1 to 3 illustrate provision of a belt 41 connecting the driven wheel 30 with the driving wheel 29. Either or both of the Wheels may be equipped with side flanges 42 or otherwise formed for keeping the belt from leaving the pulley wheels shown. It is furthermore within the scope of theinvention to augment the inherent frictional engagement of the belt with the wheels: by suitable meanssuch as by utilizing a belt or wheels or both having rough engaging surfaces, of. which the series of evenly spaced knobs 43 on the inner circumference of the belt are one example. In the particular showing of'Figs. 1 to 3, the wheels also are shown provided with knobs 44 adapted to successively engage in hollows 45 of the belt between the belt knobs, and correspondingly the belt knobs are adapted to successively engage in'hollows 46 between the Wheel knobs. The belt is properly proportioned to be taut on the wheels, and has been found'to be substantially noiseless in'itsoperation. Thus'the noise level of the shaver in use is very much reduced from that attained by prior art shavers. The driving wheel 29, driven wheel 30, the belt 41' constitute a friction drive interposed between the motor and eccentric 37. On the other hand, swinging arm 38 fixed on said blade shaft 34 and in constant engagement with eccentric 37 constitute a positive drive. The motor therefore actuates the blade shaft 34 and blades 40 by means of a friction drive and a positive drive interposed successively between the armature shaft'28 of the motor 27 andthe oscillating blade shaft 34.

Finally, it may be said that by utilization of a forked swinging arm in close riding engagement at all times on opposite sides of the eccentric, and by preventing said arm from spreading, it too will be noiseless and thus the driving means in its entirety is noiseless. It is further to be understood that although I have arbitrarily selected a shaver with oscillating blades for illustrative purposes, the invention is not confined thereto, but includes constructions of shavers utilizing blades that are continuously rotated fully around the axis of the blade shaft, in which event a frictionally driven Wheel would be carried directly upon said blade shaft and the swinging arm and eccentric omitted.

What is claimed is:

An electric shaver having a casing body, and a cap thereon, said cap having a grill, a movable blade engageable against said grill for effecting a shear with respect thereto, a movable blade carrier for said blade movable in a direction to effectuate shear by said blade, and a motor having driving connection to said blade carrier for moving said blade carrier and blade in said direction to effectuate shear, said driving connection providing in succession a friction drive and a positive drive from the motor to the blade carrier at one end only thereof, said friction drive located entirely within said casing and including a driving wheel having a friction surface and a driven wheel having a friction surface, both of said wheels mounted on said motor, and said positive drive comprising an eccentric next to and connected with said driven wheel for rotation therewith and wholly in said casing body, and said positive drive also comprising an arm riding on said eccentric and projecting from said easing into said cap to said blade carrier and attached to said blade carrier for actuation thereof and the only movement of the portion of said arm projecting from said casing being oscillatory, the same portion of said arm always projecting from and constituting the- References Cited in the file of this patent UNITED STATES PATENTS 926,509 Rankin June 29, 1909 1,351,507 Collins Aug. 31, 1920 1,847,177 Freedlander Mar. 1, 1932 2,096,379 Peak Oct. 19, 1937 2,176,335 Gray Oct. 17, 1939 2,186,110 Jensen Jan. 9, 1940 2,229,960 Dalkowitz Jan. 28,- 1941 2,260,114 Hammond Oct. 21, 1941 2,265,305 Nyhagen Dec. 9, 1941 2,270,800 Johnson et al. Jan. 20, 1942 2,284,038 Bruecker May 26, 1942 2,397,312 Forrest Mar. 26, 1946 2,474,027 Berger June 21, 1949- 2,580,138 Trought Dec. 25, 1951 2,688,184 Jepson Sept. 7, 1954 2,742,694 Stone Apr. 24, 1956- 2,797,479 Jepson- July 2, 1957 2,858,607 Kane Nov; 4; 1958 FOREIGN PATENTS 524,630 Belgium Dec. 15,1953.

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